An important requirement for pervasive computing systems is the
ability to adapt at runtime to handle varying resources, user
mobility, changing user needs, and system faults. In this paper we
describe an approach in which dynamic adaptation is supported by
the use of software architectural models to monitor an application
and guide dynamic changes to it. The use of externalized models
permits one to make reconfiguration decisions based on a global
per-spective of the running system, apply analytic models to
determine correct re-pair strategies, and gauge the effectiveness
of repair through continuous system monitoring. We illustrate the
application of this idea to pervasive computing systems, focusing
on the need to adapt based on performance-related criteria and
models.